Smoking and subgingival microflora in periodontal disease

Aim: The present investigation was undertaken to analyze the influence of s moking on the periodontal disease associated subgingival microflora. The po pulation included 33 smokers and 31 non-smokers in the age range 36-86 year s. Methods: Microbial samples were obtained from 4 sites per patient. The chec kerboard DNA-DNA hybridization technology was used for detection of the bac terial species P. gingivalis, P. intermedia, P. nigrescens, B. forsythus, A . actinomycetemcomitans, F. nucleatum T. denticola, P. micros, C. rectus, E . corrodens, S. noxia and S. intermedius. Results: Using score 1 as cutoff, contrasting colonized versus non-colonize d patients, 8 out of 12 species were detected in greater than or equal to 9 0% of both smokers and nonsmokers. Using score 4 as cutoff, contrasting hea vily colonized patients versus non-colonized and less heavily colonized pat ients, the detection rates decreased in both smokers and non-smokers. No si gnificant differences in detection rates were observed between smokers and non-smokers. Logistic regression analysis indicated that neither smoking, p robing depth nor gingival bleeding influenced the occurrence of the species analyzed. The lack of a smoking exposure dose-response further supported t he indication of a limited influence of smoking. Conclusion: Smoking exerts little, if any, influence on the subgingival occ urrence of several of the bacteria most commonly associated with periodonta l disease.